From a BMS perspective, EPO is more than just cutting power — it’s about coordinated interlocks that ensure the right sequence of actions:

✅ Shut Down via BMS
1. AHUs, CRACs/CRAHs, and non-essential fans to stop smoke spread
2. Chilled water pumps or equipment serving the affected zone
3. Normal lighting and non-critical loads

✅ Release / Fail-Safe
1. Door locks & magnetic holders released for safe evacuation
2. Dampers driven to fire-safe positions

✅ Start / Keep Active
1. Smoke exhaust & stairwell pressurization fans Emergency lighting circuits
2. Fire alarm & life-safety devices (stay ON, not cut by EPO)

👉 For a BMS engineer, the challenge is ensuring correct interlocks, point mapping, and sequencing so that when EPO is pressed, the building reacts safely and reliably.

Well-designed BMS logic ensures that “EPO OFF” is not chaos, but controlled safety